(^2) an environmenTal hisTory of Wildlife in england
call succession. Plants colonized in a more or less predictable sequence, each
creating conditions which allowed successors to establish and flourish, leading
in time to the development of a climax vegetation of closed-canopy forest
which survived until the arrival of farming soon after 4,000 BC. Following
this, most of England was cleared of trees, but if land is abandoned for
any length of time succession begins once again, and within a short period,
grasses and herbs will give way to scrub, and scrub to woodland.
In the course of the twentieth-century palynology, the study of pollen
grains preserved in waterlogged conditions, changed perceptions of the
character of the prehistoric ‘wildwood’. People had assumed that this had
been dominated by oak, understandably given the prominence of this species
in surviving examples of ancient woodland. But it now became clear that
small leafed lime (Tilia cordata) had been the most important component of
the post-glacial vegetation across much of lowland England, accompanied
by varying mixtures of oak, hazel, ash and elm, and with pine and birch
being locally important. In the north and west, lime was rare and pollen
cores suggest instead the presence of woodlands comprising diverse mixtures
of oak, hazel, birch, pine and elm.^2 But while pollen analysis thus changed
our ideas about the composition of the ‘wildwood’, it did not challenge the
basic idea that England had, before man began to make extensive clearances,
been more or less continuously wooded. In 1986, however, Oliver Rackham
suggested that some areas of more open ground must have existed as part
of the country’s natural vegetation;^3 while 4 years later such ideas were
taken much further by the Dutch ecologist Frans Vera. He drew attention
to the importance of oak and hazel in pre-Neolithic pollen cores, noting
that these species do not flourish in closed-canopy conditions. The pollen
of various trees and shrubs more characteristic of woodland edges, than of
continuous woodland, was also prominent, including that of blackthorn,
hawthorn, rowan, cherry, apple and pear; so too was that of wood-edge
herbs like mugwort (Artemisia vulgaris), nettle (Urtica dioica) and sorrel
(Rumex acetosa).^4 Vera suggested that succession to closed-canopy forest
had been checked by the grazing of large herbivores such as auroch (wild
cattle) and deer. The ‘natural’ landscape had, in fact, been ‘park-like’ in
character, with areas of open grassland, scattered with trees; patches of
scrub; but only sporadic stands of denser woodland. Vera conceded that the
pollen evidence superficially indicated a landscape dominated by woodland,
rather than by open pasture, but he argued that intensive grazing would
have ‘limited the flowering of grasses, and thus the pollen emitted by grass
into the atmosphere’, thus hiding the true character of the vegetation.^5 He
also noted that oak and lime emit more pollen when growing in open, park-
like conditions than when crowded together in dense woodland.
In addition, Vera suggested that the pre-Neolithic landscape had been
more dynamic in character than the conventional concept of the stable,
climax ‘wildwood’. It included patches of thorny scrub where trees were able
to seed and grow, protected from grazing animals. As these reached maturity
elle
(Elle)
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